Any 5.9 Cummins guy's on here?

capercal

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Sorry but this may sound dumb but could the hot /cold knob or switch be no longer working and be stuck toward the cold side? Thing do wear out
 

Nathansharkey

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I've got an 02 5.9 cummins,that as many of you already know are
famous for not making any heat at sub 0 temps.Any guy's that do
or have previously owned one take the fan off for the winter?
Stupid clutch fan is not locked up but still turning at 80% of crank
speed when the engine is stone cold.I have a chip that has a high
idle feature(not working at the moment)but at minus 20 this thing
can idle all day and still blow cold air.Any thoughts?
Thank's

Have you checked the coolant levels?
 

Badass69

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If the stat is closed it wont mater if the fan is turning because you have no-flow through the rad.

Ever heard of wind chill? It affects anything that can lose heat.... including an engine. Frozen viscous clutch fans are garbage in the winter...... With that stupid monstrous thing roaring under the hood locked on because the clutch is froze. I don't drive diesels for a multitude of reasons but this will affect either or in the same manner. Even with the thermostat closed that lovely fan will do everything in it's power to ensure it never opens either. I trash the clutch fan junk on my trucks for e fans but again I am not a diesel owner.

Every friend I have ever had has complained about the lack of heat with their Cummins.... The 5.9's I used to run in equipment were no different, took forever to warm up in the winter and cooled off instantly without load.
 
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mdwils

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Ever heard of ambient air temperature? Its what causes things to cool. Mammals like us humans feel wind chill.
I used to cover just the rad behind the CAC, But after I started covering the CAC too it was like nite and day. I used canvas type stuff and ziptied it to whatever I could. Almost worked as good as belly wrapping. Try covering everything, worked on my 98, 02, and 05. If I was to do it again Id have some type of flap on the front, like maybe on a button cuz at about -1 they'd start to run hot.
Btw, my Dmax is a cold blooded bitch and GM makes the winter front cover EVERYthing.
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BIG DAWG

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silly question but what setting do you have your fan at for heater if its on high good luck, with it on low it works alot better and on my 12 set like this with eng brake on shes 1/4 temp in 15min but even without eng brake 30 min like this would be 1/4 on my 02 and 05
 

mdwils

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Yup, the fan cut back one notch helps too for cab heat. And recirc. When ever yur not sitting in it.

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somethingnuw

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No,thermostat isnt stuck.Yes I have a weather front on it.Clutch fan just pi**'s me off turning all of the time
and the engine is stone cold.Unless you drive it for 5 miles,it can idle all day and you get zero heat.
Temp gauge is always bottomed out.I could belly wrap it or something,but the clutch fan is still gona be blowing
cold air all over.

mine with winter front and running needs about 20 k to get to full running temperature... then if i stop and idle it does cool down quickly... but if I keep in running only takes a few km's to get nice and warm again... if it's any worse then that id say you have a problem...
 

somethingnuw

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silly question but what setting do you have your fan at for heater if its on high good luck, with it on low it works alot better and on my 12 set like this with eng brake on shes 1/4 temp in 15min but even without eng brake 30 min like this would be 1/4 on my 02 and 05

speaking of which... i had heater core replaced now heat only blows on high??? not trying to steal a thread but anyone else have this problem? Dodge in High Prairie said this is what their after market blowers do... i was like F*** O** never going there again
 

Badass69

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Ever heard of ambient air temperature? Its what causes things to cool. Mammals like us humans feel wind chill.
I used to cover just the rad behind the CAC, But after I started covering the CAC too it was like nite and day. I used canvas type stuff and ziptied it to whatever I could. Almost worked as good as belly wrapping. Try covering everything, worked on my 98, 02, and 05. If I was to do it again Id have some type of flap on the front, like maybe on a button cuz at about -1 they'd start to run hot.
Btw, my Dmax is a cold blooded bitch and GM makes the winter front cover EVERYthing.
Sent from my Galaxy using Tapatalk 2

Lol. You do realize although not a living creature an engine or any other heat source for that matter can be effected by wind chill..... No a cold chunk of steel in the wind will be and stay at ambient...... but something that has heat to give up ( human body, engine, heater or otherwise) will be negatively effected by the wind compounding the issue. If you want I can just call it heat transfer from here on.

I have proven this over and over and over but whatever. My trucks with electric fans warm up more easily....... but moreso hold heat when idling. When they had the clutch fan it being locked by temperature would cool the truck until the thermostat closed again..... and subsequently slowly would cool the truck off in cold weather diminishing available heat to the cab. Now without that useless thing on the front of the engine that doesn't happen because of course air is not being drawn across the radiator cooling it. The radiator is still sitting in the same -25 C ambient just like it did when the truck had a clutch fan..... but now lacking that clutch fan it no longer gets cooled by heat transfer from the fan spinning. So with that lack of airflow -25 is just -25 and it doesn't negatively impact the cooling system....... Just like you standing in -25 weather with no airflow( wind) or standing in -25 with a 60 km/hr wind blowing..... same thing. The truck will stay at full operating temp even in -30 C ambient without a winter front or otherwise while idling for extended periods of time. That alone was worth the switch..... plus less noise and of course air conditioning that works properly in the summertime.
 
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Stefan Plouffe

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Fastest way to warm em up is put it on maybe med heat and recirc. Technically the thermostat is keeping any fluid from flowing thru rad so blocking it off won't help much. There might be tiny bypass amount that goes to rad, that's it. The amount of heat loss through the block into the ambient air might be a bit less with cold front or belly wrap but if there is much wind at all, that won't help. Point is, the heat lost through transfer to air is minimal. The heat lost from the rad is minimal.

Most of the heat loss is to the massive cfm's of air that are being drawn over your heater core with the fan on full tilt and drawing in freezing cold outside air over what is basically a radiator, just inside your truck.

The engine block, fluids etc of a diesel when all at minus who knows temp are so much that it takes an incredible amount of BTU's just to heat the steel and fluid up not to mention the liters of tranny oil that also go thru a cooler... point here is you could bypass radiator altogether, take the fan off and have zero ambient air blowing over or around the truck and if it's -30 out... that truck at idle will take 20 - 40 min to warm up enough to blow hot air. If you have the heater on full blast sucking outside air in. It would most likely not heat up in an hour if at all. The engine is inherently so efficient that it does not create enough BTU's of heat energy to make it happen.

Believe me the recirc thing works. Yes you can't have it on defrost and recirc at the same time.
 

Badass69

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Believe me the recirc thing works. Yes you can't have it on defrost and recirc at the same time.

Not on all manufacturers trucks....... neither of mine will allow recirc to function with defrost. I know Dodge does or should I say did, and has for a long time so maybe that can help out the chilly Cummins drivers, lol.
 
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